Soil squeezing effect of installation of pipe pile casing

Abstract:

During the casing penetration process, soil squeezing effect has a negative effect on the quality of the construction, which forces the soil around the pile to deform. Based on the large deformation finite element (LDFE) analyses using remeshing and interpolation technique with small strain (RITSS), a numerical model of pipe pile penetrating in soft clay was established, and numerical results were compared with field test data to verify the accuracy of the model. Then, a parametric study was carried out to examine the influences of pipe tip geometries and soil strength on the characteristics of soil movement induced by casing penetration. Results show that by taking the penetration depth of L_p/R=8 as the critical point, it could be divided into shallow penetration mode and deep penetration mode during the process of pile casing penetration. The soil flow mechanism was different in different penetration areas. The horizontal displacement of the soil and the soil heave outside the pile were closely related to the angle of the spudcan. According to the numerical simulation results, based on the casing penetration results of the commonly used spudcan (β=60°, w_p=0.01 m) in practice, formulas for predicting horizontal displacement and soil heave were proposed. Compared with field test data, the proposed formulas could effectively predict the soil deformation around the pile. The research findings provide a theoretical guidance for the design and construction of cast-in-situ concrete piles (PCCs).